1. 通过剪切板来实现。
public void InsertImage() {
string lstrFile = fileDialog.FileName;
Bitmap myBitmap = new Bitmap(lstrFile);
// Copy the bitmap to the clipboard.
Clipboard.SetDataObject(myBitmap);
// Get the format for the object type.
DataFormats.Format myFormat = DataFormats.GetFormat (DataFormats.Bitmap);
// After verifying that the data can be pasted, paste
if(myRichTextBox.CanPaste(myFormat)) {
myRichTextBox.Paste(myFormat);
}
else {
MessageBox.Show("The data format that you attempted site" +
" is not supportedby this control.");
}
}